Case Study #4  Thermal Rating Program

This international heat transfer equipment manufacturer needed to re-engineer a text-based MSDOS engineering application from unstructured, undocumented Fortran 77 into a Windows-compatible Graphical User Interface on the front end with a SQL Server database for data storage and retrieval on the back end, while insuring seamless integration with other custom legacy applications that the client uses.

At the point of engagement, the Client was using a text-based MS/DOS console application for thermal engineering design and certification, which was composed of 25,000+ lines of unstructured and undocumented Fortran 77. The application performs text-based console I/O and uses ASCII text and binary files for data retrieval and storage. Additionally, the output from this application is exported to an Excel spreadsheet stored on a network file share for additional processing, and then fed to additional down-line applications.

Several engineering options were suggested by Stonebridge. As a first step, Stonebridge provided services to structure the FORTRAN code, map out the I/O functions and convert the application to ANSI Standard C code. After structuring, documenting and mapping all of the functions and I/O within the existing FORTRAN code, Stonebridge migrated the code into C++ and validated that output calculations were identical to the original program.

After this step, the application was compiled and running as a Visual Studio .NET 2003 console application with a C++ wrapper. At this point, the design options discussed for interfacing a GUI with the C code were: (a) Convert the application into COM+ objects and create an ASP.NET-based GUI using C#, (b) Convert the application into XML Web Services and create InfoPath forms for the GUI. The client’s preference was Web Services, because of the flexibility offered by the XML-based interface.

In the final system, the GUI will be a set of InfoPath forms connected to the XML Web Services application as well as directly to the SQL Server 2000 database. As each of the custom legacy applications is re-engineered into Web Services, they will be added to the main form. Finally, corporate data will easily flow between applications as XML documents. The security model will be based on Windows Integrated security and will allow access on role-based group membership.